The Pathology Core will provide coordination for all pathology activities within the program project including histologic, morphometric, immunologic and molecular analysis of tissue. This will reduce duplication of effort among the different projects and allow a degree of expertise that would be difficult to achieve in any single project. Along with the technical advantages of a single morphologic core, the use of a single principal pathologist will also promote uniform analysis of results allowing more ready comparison among the projects. Furthermore, by providing uniform access to specialized morphologic techniques, this facility will form a focal point for collaboration among members of the grant. Technical services provided include routine paraffin embedded histology, electron microscopy, immunohistochemical stains on frozen and paraffin embedded tissue, and in situ analysis for mRNA. The results will be analyzed by a pulmonary pathologist for nature and extent of inflammatory change, microanatomic location of the infiltrate, presence of airway or other tissue remodeling, and presence of epithelial injury. Any changes identified will be quantified by morphometry where appropriate. The core director has successfully served as director for a previous asthma SCOR grant. He thus has a full working relationship with all current program project members. Furthermore, due to this previous experience, the Core has achieved a level of excellence that would have been difficult to achieve in any other environment and will be difficult to continue in the absence of program project support.